Bolt ejector for thread rollers



Dec. 3, 1946. 1 1 MITCHELL 2,411,932

OOOOOOOOOOOOOOOOOOOOOOOOO RS Patented Dec. 3, i946 Y BOLT EJECTOR ENT oFFlcE l.

lLouis J. Mitchell, Cleveland, Ohio, assignor, by j mesne assignments, to Jack & Hentz Precision Industries, Inc., Cleveland, Ohio, a corporationv of DelawareA Application June 16, 1945, Serial No.l 599,718

i tice tohave one threaded die adjustably secured to the stationary frame of the 1machine and to have a complementary threaded die adjustably secured to a movable carriage which latter is ad- .instable to bring its threaded die into predetermined spaced parallel relationship with the stationary die, the carriage beingv automatically driven back and forthl parallel with the frame at a predetermined speed and length of stroke at least equal to the length of one of the dies. The Work may comprisean unthreaded bolt which is fed into the space between the dies at -thestar-t ofthe stroke of the movable driven die. The bolt is compressed between the dies and rotatably carried to the opposite endv of the stationary die by Ithe driven die While the bolt is having a spiral screw thread pressed thereinto.` It is of utmost importance that the bolt be positively ejectedat the completion of this forward stroke. Failure of such ejection results in the bolt being carried back between the dies on the backstroke and a consequent ruining of the bolt and, more important, the damaging of both of the expensive threaded dies. Experience has shown that gravity alone or ineilicient makeshift ejection devices lacking in positiveness cannot be relied upon for the highly important feature of ejection.

It is, therefore, one of the primary objects of the present invention to provide such a positive automatic work ejecting device whose action is so `correlated between the relative movements of the two relatively movable threaded dies that it will remain out of the path of the bolt during its forward travel between the dies and be actuated at 4a predetermined point in such 4travel to follow the bolt and` moreover contact the latter in full length flatwise engagement to positively eject the .threaded bolt at the very end of the stroke just prior to the start of the back stroke.

With the foregoing and other objects in view, the invention resides in the combination of parts and in the details of construction hereinafter set forth in the following specification and appended claims, certain embodiments thereof being illustrated in the accompanying drawings, in which:

Figure l is a View in perspective of a portion of a thread rolling machine showing one threaded die carried by the stationary frame and another carried by a reciprocating carriage showing the 2 claims. (01.' slr-s) adjustable bracket for supporting the work eject- 55 kstationary frame I.

ing device carried by the frame and showing the carriage in the midst of its work threading stroke; Figure 2 is asimilar View with the frame broke-n away to show the position of thework ejecting device in inoperative horizontal position yat the star-t of the forward stroke of the carriage; Figure 3 is a view similar-to Figure 2 near the completion ofthe forward stroke of the carriage showing the work ejecting lever raised from its previous horizontal position to a vertical position to eject the work at the completion ofthe stroke; Figure 4 is a detail view in elevation of a double land bolt after spiral threads have been pressed therein;

Figure 5 is an enlarged detail View -in si-del elevation ofthe work ejection device in the vertical yposition and taken along line 5 5 of Figure 3; Y

Figure 6 is a v-iew similar to Figure 5 showing the work ejection -device in inoperative horizontal vpositionv and taken along line6-6 of Figure 2;

Figure 7 is an enlarged detailend view .of the bracket for supporting the work ejecting device.

Referringmore particularly to the drawings, the stationary frame I has adjustably secured thereto a block 9 to which is secured by a suitable bracket 2 and bolt 3 a thread die'4. Mounted Yslidably on the frame is a carriage 5 that also has adjustably secured thereto by a suitable bracket 6 and bolt 'I a thread die 8. The two opposed faces of the thread dies are so threaded as to press the work, such as a bolt, to form a continuous spiral screw thread as it is rolled by the relative longitudinal parallel movement of the die faces which engage the bolt. The adjustability fof the ltwo dies, in accordance with usual practice, should be such as permit Vertical longitudinal and lateral adjustment to respectively adjust alignment of threads, effective length of reciprocatory stroke of the carriage and the space between the threaded faces for dilferent thicknesses of work to be engaged between the threaded faces.

The Work ej ecting device is carried by a bracket IIJ having a pair of elongated slots II to receive bolts I2 to adjustably secure .the bracket to the This bracket has pivotally secured -to its other end at I3 the work ejecting lever I4. Lever I4 carries a pin I5 that rides on a ledge I6 of the carriage 5 Ibelow its die 8. Bracket I 0 has a .pin I1 around which is hooked one end of a tension coil spring I8 whose other end is hooked to lever I 4 below pin I3.

Figure 2 shows the relative positions of the carbetween the two thread dies.

riage and the lever I4 prior to the beginning of the forward stroke of the carriage. The lever I4 is horizontal as pin rests on 'ledge I6 of the carriage Well below the lower edge of the carriage die 8, as well as that of the base die 4. It is at this point in the sequence of operation that the worksuch' as a bolt I8, shown in Figure 4 as having twofspaced lands 20 and 2I, is inserted in a vertical attitude between the front portion of the carriage die 8 and the rear portion of the base die 4. Prior to such insertion the lands are unthreaded and have a smooth exterior surface.

Forward movement of die' 81 carries the bolt forwardly as the latter is compressed and rotated in engagement with the threads of the two dies 8 and 4. During the major portion of the forward travel of carriage 8 the bolt ejecting leverY I4 remains in its horizontal position of Figure A2 completely out of the path of travel of the bolt At practically the completion of the'i'or'ward stroke of the carriage its rear vertical ledge'Z'rZ,` whichy is in alignment ywith therear edgefof die 8, engages vpin YI5 of the ejecting lever. VThis rocks lever I4 in a counterclockwise direction from its horizontal position of "Figure 2- to its vertical position of Figure 3 about its pivot I3 against the action of tension coil spring I8. 'The height vof lever I4 is preferably vsuilcient to extend atleast to the top edges of the dies and consequently engages a substantial portion of the length of the bolt, if not all except the bolt head. This timed action of the ejecting lever I4 insures a positive ejection of the bolt after it has had its spiral threads pressed into its lands, as shown in Figure 4.

It lfollows that the backstroke which starts immediately after the ejection of the bolt removes the pressure of wall 22 upon pin' I5. Consequently spring, I8 exerts its force to Vrock lever I4 counterclockwise about pin I3 from a vertical position of Figure 3 back to its horizontal inoperative position of Figure 2 as the two thread dies are in position to receive another bolt for another threading operation.

I claim:

1. In combination with a thread rolling machine having a pair of dies with opposed threaded faces one of which is carried by a stationary frame and the other by a carriage reciprocably movable parallel therewith in spaced relation to receive therebetween a bolt to be carried forward by the forward stroke of said carriage as the bolt is rolled and compressed to have va continuous spiral screw thread pressed thereinby the threads of saiddies, a device for ejecting said bolt upon completion of the forward stroke of the carriage and prior to the start of the backstroke thereof, said ejecting device comprising an adjustable bracket carried by said frame and carrying a pivoted 'lever operable within a plane lying betweensaid die faces and normally maintained horizontal and vbelow the lower edges thereof, means on said lever engageable by said carriage near the end of its forward stroke for operating said =lever to swing it into a Vertical position to engage the major portion of said bolt in fiatwise Contact from the rear to Vpositively eject .the

same.

2. In combination with a thread rolling machine having apair of dies with' opposed threaded faces one of which is carried .by a 4stationary frame and the other by Ya carriage reciprocably movable parallel therewith in spaced relation to receive therebetween a bolt to 'be carried forward by the forward stroke-of said carriage as the bolt is rolled and compressed tohavea continuous spiral screw thread pressed therein by the threads of said dies, a device forv ejecting said bolt upon completion ofthe forward stroke of the carriage and prior to the startlof the backstroke thereoisaid ejecting device comprising an vadjustable bracket carried by said 'frame-and carrying a pivoted .lever operable' within a plane lying between saiddie 'faces and springmeans l,for normally maintaining said lever' horizontal and below the lower edges of'said dies, a pin carried by said lever to be engaged by a groove in said4 'carriageand adapted to be' forcedby the rear end of said groove near Vthe completion cf the forward stroke of the carriage 'to rockv the lever` about its. pivot against 'the action of said spring into a vertical attitude andinto atwse Contact with the length of the bolt to `positively eject the same. 

